When it comes to running socks, Smartwool pulls out all the stops to keep making improvements on their products. With brand-new Shred Shield™ technology to help improve wear in the toe box, Smartwool's PhD® Run Ultra Light Micro socks feature the 4 Degree™ elite fit system and their Indestructawool™ technology for a dialed-in fit and improved durability.


  • Indestructawool™ technology for enhanced durability
  • 4 Degree™ elite fit system for a dialed, performance-oriented fit
  • Shred Shield technology reduces wear from toes
  • Body-mapped mesh zones for added breathability
  • Virtually Seamless™ toe for enhanced comfort
  • Achilles tab designed to prevent sock from slipping down into footwear


Length: No Show
Weight: Ultra Light
Material: 45% Merino Wool, 50% Nylon, 5% Elastane